1. Field of the Invention
The present invention relates to a resilient device allowing an electrical connection to be made in a connection terminal for electrical conductors.
2. Description of the Prior Art
It is known to use springs for maintaining the end of a stripped conductor against a current supply rail in a connection terminal. Documents DE-3,727,091 and EP-0,823,752 describe connection terminals of this type. In these documents, there is a pinching spring made from a flat resilient material shaped in a kind of loop. The pinching spring has a stop branch intended to bear on a current rail, as well as a pinching branch bent over from the back part of the pinching spring, extending transversely to the current supply rail, as well as a resilient arc joining together, via the rear, the back part and the stop branch. The pinching branch is provided with a pinching cavity. The current supply rail passes through said pinching cavity. The spring is such that, when the stripped end of an electrical conductor is inserted into the pinching cavity, the spring presses the stripped end of this wire against the current supply rail.
A device of this type can also be used for making an insulation-displacement connection for an electrical cable. In this case, the spring serves to store the energy necessary for stripping an electrical cable and to jam it in a connection slit, and then to release this energy.
Document FR 2,753,840 describes a connection terminal which includes a pinching spring and which is reduced in size in the direction transverse to the insertion of a conductor. The resilient arc of this spring is shaped in such a way that, starting from the rear part of the pinching spring, the resilient arc is placed at a position, over at least part of its arc, below a bearing plane defined by the extension of the bearing branch of the pinching spring. A cavity is then provided in the current supply rail so as to house the resilient arc of the spring.
In the known springs, the internal stresses which appear when the spring is tensioned are very high, especially in the resilient arc. For a given thickness of material, the deformation of the spring is therefore limited in order not to run the risk of damaging the spring. Consequently, one also obtains a limited tensile force exerted by the spring.